1. Field of the Invention
The present invention relates to a method and an apparatus, both designed to analyze a sample by applying propagation rays, such as X-rays and particle beams, to the sample.
2. Description of the Related Art
A method of analyzing a sample by applying propagation rays, such as X-rays, to the sample is disclosed in, for example, Japanese Unexamined Patent Publication No. 2001-349849. In the method disclosed in the publication, an X-ray scattering curve simulated of a thin film is compared with an X-ray scattering curve measured of the thin film, in order to evaluate the non-uniformity of density of the particles contained in the thin film.
To simulate the X-ray scattering curve, a scattering function I(q) is set in advance. The scattering function I(q) includes one or more fitting parameters selected from parameters pertaining to the scattering state of particles. Among these parameters are average particle size parameter “R0,” distribution-broadening parameter “M,” diameter parameter “D,” aspect-ratio parameter “a,” minimum inter-particle distance parameter “L,” inter-particle correlation coefficient parameter “η,” particle-content parameter “P,” inter-particle distance parameter “ε”, and the like.
The simulated X-ray scattering curve may coincide with the X-ray scattering curve actually obtained. In this case, it is determined that the values of the fitting parameters simulating the X-ray scattering curve represent the scattering state of the particles in the thin film.
This method can analyze thin films in non-destructive fashion, more easily, more quickly and more precisely than the gas adsorption and the small angle X-ray scattering, both hitherto known.
Japanese Unexamined Patent Publication No. 2001-349849 describes in, for example, paragraph [0086] that the scattering function actually acquired can be effectively corrected by using a slit function, in order to correct the error that has resulted from the limited length of the slit. However, the slit function disclosed in Japanese Unexamined Patent Publication No. 2001-349849 is very simple. Due to this, the slit correction may not be accomplished as precisely as desired in the optical system employed in practice.